adjusting rear ride height

[yeuporsch]

I am using the tripod method to adjust the ride height. I got the angle set evenly on both side. However, after setting the car down and taking it for several test drive, one side is still higher than the other by about an inch. Is this unusual? Could there be other problem that can affect this, ie, shock, torsion bar?

Or should I keep adjusting using the tripod method to corner weight the rear. The angle will be different; is this ok?

Thanks,

John

[imcarthur]

Hmmmm.

Is your garage perfectly level?
Are you 'driver' weighting the car?
Is the emergency brake off with 3/4 fuel?
Have you replaced the springplate bushings?

Because the cars are not built perfectly symmetrical & x number of years of wear & tear I wouldn't expect 100% accuracy with the angle but it does sound off by a bit too much.

Ian

[fuelie600]

John,

An inch does sound like too much. In addition to Ian's comments, did you disconnect the anti-roll (sway) bars?

I had/have the same problem with my car. I used the tripod method to set the corner balance using the torsion bar centers to measure height. When it was finsihed I found the body measurements are off by about 3/8" side to side. My passenger side sits lower than the drivers. I went back and re-measured the tripods and they were dead on.

I plan to re-adjust in the spring to compensate for the difference. Might be a good excuse to do some more mods....

[edward993]

John,

Where are you measuring that you're getting a 1" discrepancy? Don't use any body points ...the bodies vary, especially over the years and possibility of body work or whatever. I measure from the floor to the bottom of the torsion bar cover, or any fixed chassis point, not body point. And as mentioned, make sure your swaybars are disconnected and your floor is level. FWIW, I was able to mine L-R heights within 1/4"

Edward

[yeuporsch]

The garage floor is level. I had new bushings in rear, hence the need to readjust. The car was not level before. I measured at the torsion bar. I will pull the shock absorber on the affected side to see if there is a problem there. The anti roll bar was disconnected. I did measure at the rear torsion bar with the rear raised. The difference was less than a 1/4 in.

John

[fuelie600]

Originally posted by yeuporsch
.... I had new bushings in rear, hence the need to readjust.

What type of bushings did you use? Any chance they are binding? Did you settle the suspension before measuring?

...The car was not level before.

Was it off by an inch before? any chance it's been hit?

I did measure at the rear torsion bar with the rear raised. The difference was less than a 1/4 in.

Raising the rear won't work for measuring the rear torsion bar heights.

[JP911]

Before you redo your work, try taking a passenger with you on your test drive that weighs about the same as you. When I did new bushings, T-bars, and shocks I went through the same thing. The car just needed to be weighted evenly in order to settle.

[Thrasher]

I did this last year and found that my RF fender was off a bit after all was done. I adjusted everything using suspension heights, not body heights, as I am using performance first, aesthetics second.

Not that they should be mutually exclusive, but if your 20-30 y.o. car has ever been bumped, the tub may not be perfect any more, so one or the other has to give (or both to a lesser extent as a compromise).

In any event, my car balanced on the scales to within 19 lbs on the diagonals after my tripod adjustments. You'll want to revisit your fronts after you get the rears set, as there is a profound effect on the front as well when you adjust the rears.

IIRC, Grady Clay also suggested leaving non-adjustable swaybars connected for this adjustment, since that will be how the car is ultimately driven. You could use some washers to minimize the preload on your swaybars if it's really inducing that much load at rest.

Craig

PS: I also never got anywhere close to the factory hub center to t-bar center numbers - I used absolute height from the (level) floor and made certain that it was consistent left-right (to within a few mm). The absolute height was determined by whatever got me closest to the fender height I desired. It took a lot of iterations, but was a good learning exercise for me.

[yeuporsch]

"I did measure at the rear torsion bar with the rear raised. The difference was less than a 1/4 in. "

I meant that I measured the rear after the front were set using the tripod method. I then raised the rear using the tripod method and measured the difference in the side to side height at the torsion bar, and the difference was 1/4 in.

I also take the car out for several spin before rechecking the measurement.

John

[Thrasher]

You need to make sure you settle that suspension adequately between each axle raise (front or rear). You may have some "stiction" in your new bushings that makes things hang up, so don't be shy. I tried bouncing them manually, then zigzagging heavily on the settle-in drive.

Given how much simpler the front is than the rear, I'd save it for last if I were you (although theoretically the tripod method removes rear influences on the front and vice versa).

You may also want to add some ballast (I used bags of water softener salt) to your driver seat. Although my first DE gave me a 260 lb instructor in the passenger seat.